U.S. Severe Weather Forecast (Coup d'œil sur la convection)

Aujourd'hui
Demain
Day Three

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swody1 
Storm Prediction Center ac 260557 


Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1157 PM CST Tuesday Nov 25 2014 


Valid 261200z - 271200z 


..no severe thunderstorm areas forecast... 


... 
thunderstorms will be possible across the southern Florida Peninsula 
and the North Carolina Outer Banks through the morning. 


... 
The overall large-scale pattern will begin to trend toward a 
somewhat less amplified regime through early Thursday. Phasing 
shortwave troughs over the eastern third of the Continental U.S. Will 
contribute to steady surface cyclogenesis along the East 
Coast...with a cold front continuing to move across South Florida early 
today. Any thunderstorm potential will be relegated to South Florida and 
the coastal NC vicinity. 


..coastal NC... 
It is likely that the warm sector will largely remain 
offshore...although steady surface cyclogenesis in vicinity of the 
coastal Carolinas should allow for the coastal front/warm sector to 
at least graze the Outer Banks of NC this morning. This expected 
frontal/stable thermodynamic scenario should limit the inland severe 
potential in an otherwise favorable wind shear 
environment...although some embedded thunderstorms will nonetheless 
be possible this morning. 


..South Florida... 
Bands of showers/embedded thunderstorms will continue to accompany 
an eastward-progressing cold front this morning...with thunderstorms 
generally ending by late morning as the front accelerates offshore. 
Severe potential early today /12z Wednesday and beyond/ will likely 
be mitigated by the frontal timing/veering low-level flow and a 
modest amount of boundary layer inhibition. 


.Guyer/leitman.. 11/26/2014 

Mesoscale Discussion


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sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 251913 
flz000-252115- 


Mesoscale discussion 1954 
National Weather Service Storm Prediction Center Norman OK 
0113 PM CST Tuesday Nov 25 2014 


Areas affected...portions of central Florida 


Concerning...severe potential...watch possible 


Valid 251913z - 252115z 


Probability of watch issuance...40 percent 


Summary...thunderstorms are increasing in coverage over the eastern Gulf 
of Mexico...and the risk for isolated damaging wind gusts and 
perhaps a tornado continues this afternoon across portions of central 
Florida. A ww may be considered over the next several hours if storms 
strengthen as they move onshore near Tampa and vicinity. 


Discussion...showers and elevated thunderstorms continue to form 
along and north of a west-east oriented boundary from just north of tpa...to 
mco...to tts across central Florida. These storms pose a very limited risk 
for severe weather as they move northward into a drier and more stable air 
mass. Along and S of this surface boundary the atmosphere is 
characterized by dew points in the low to middle 70s and weak to 
moderate instability...with MLCAPE generally between 500-1500 j/kg. 
Effective shear of 40-50kt will support the organization of any 
storms forming S of the boundary...and isolated damaging wind gusts 
will remain the primary severe weather threat in the short term. 
With 0-1km shear weaker at 10-20kt...the tornado threat remains 
limited. 


Semi-linear convection has also increased in coverage over the eastern 
Gulf of Mexico over the past several hours as a surface low forms in the 
same area....and these storms are slowly approaching the west-central Florida 
coast. The combination of weak to moderate instability and 
sufficient effective shear suggest that this line of storms should 
be able to maintain itself through the afternoon...and may 
eventually pose an isolated damaging wind threat for portions of 
west-central Florida. 


.Gleason/Thompson.. 11/25/2014 


..please see www.Spc.NOAA.Gov for graphic product... 


Attention...WFO...mlb...tbw... 


Latitude...Lon 28238283 28468248 28398196 27528127 27098170 27238263 
27858291 28238283